Using dynamic flux chambers to estimate the natural attenuation rates in the subsurface at petroleum contaminated sites

2018 ◽  
Vol 619-620 ◽  
pp. 470-479 ◽  
Author(s):  
Iason Verginelli ◽  
Roberto Pecoraro ◽  
Renato Baciocchi
Keyword(s):  
Natural Attenuation ◽  
Contaminated Sites ◽  
Flux Chambers

Comparison of field-observed and model-predicted plume trends at fuel-contaminated sites: Implications for natural attenuation rates

2005 ◽  
Vol 7 (11) ◽  
pp. 1099 ◽  
Author(s):  
Seung-Woo Jeong ◽  
Donald H. Kampbell ◽  
Youn-Joo An ◽  
Bruce M. Henry
Keyword(s):  
Natural Attenuation ◽  
Contaminated Sites

Robustness of an aerobic metabolically vinyl chloride degrading bacterial enrichment culture

2011 ◽  
Vol 64 (9) ◽  
pp. 1796-1803 ◽  
Author(s):  
He-Ping Zhao ◽  
Kathrin R. Schmidt ◽  
Svenja Lohner ◽  
Andreas Tiehm
Keyword(s):  
Vinyl Chloride ◽  
Natural Attenuation ◽  
Enrichment Culture ◽  
Contaminated Sites ◽  
Contaminated Groundwater ◽  
Chlorinated Ethene ◽  
Equimolar Concentration ◽  
Bacterial Enrichment ◽  
Ph Tolerance

Degradation of the lower chlorinated ethenes is crucial to the application of natural attenuation or in situ bioremediation on chlorinated ethene contaminated sites. Recently, within mixtures of several chloroethenes as they can occur in contaminated groundwater inhibiting effects on aerobic chloroethene degradation have been shown. The current study demonstrated that metabolic vinyl chloride (VC) degradation by an enrichment culture originating from groundwater was not affected by an equimolar concentration (50 μM) of cis-1,2-dichloroethene (cDCE). Only cDCE concentrations at a ratio of 2.4:1 (initial cDCE to VC concentration) caused minor inhibition of VC degradation. Furthermore, the degradation of VC was not affected by the presence of trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (1,1-DCE), trichloroethene (TCE), and tetrachloroethene (PCE) in equimolar concentrations (50 μM). Only cDCE and tDCE were cometabolically degraded in small amounts. The VC-degrading culture demonstrated a broad pH tolerance from 5 to 9 with an optimum between 6 and 7. Results also showed that the culture could degrade VC concentrations up to 1,800 μM (110 mg/L).

Natural bioremediation perspective for BTX-contaminated groundwater in Brazil: effect of ethanol

1996 ◽  
Vol 34 (7-8) ◽  
pp. 311-318 ◽  
Author(s):  
Henry X. Corseuil ◽  
Pedro J. J. Alvarez
Keyword(s):  
Natural Attenuation ◽  
Cost Effective ◽  
Hazardous Substances ◽  
Contaminated Sites ◽  
Great Promise ◽  
Rational Basis ◽  
Laboratory Studies ◽  
Significant Progress ◽  
Cost Effective Approach ◽  
Risk Protection

Natural bioremediation, the use of indigenous microorganisms to degrade hazardous substances within aquifers without engineered stimulation, shows great promise as a cost-effective approach to hydrocarbon plume management. This technique requires thorough site characterization and monitoring to verify that the natural attenuation processes continue to provide adequate risk protection. Significant progress has been made towards understanding the hydrogeochemical and microbiological factors that influence the feasibility of natural bioremediation of fuel-contaminated aquifers in North America and Europe. Nevertheless, this experience should be extrapolated with care to contaminated sites in Brazil, where gasoline contains about 22% of ethanol. Preliminary laboratory studies show that ethanol can enhance the solubilization of BTX in water, and it might exert diauxic effects during BTX biodegradation. A better understanding of the biochemical, physical, and ecological effects of ethanol is needed to develop a rational basis for the selection, mathematical modeling, and monitoring of appropriate natural bioremediation systems in Brazil.

scholarly journals Nitrate consumption by the oxidation of sulfides during an enhanced natural attenuation project at a contaminated site in Berlin, Germany

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Thomas Fichtner ◽  
Axel René Fischer ◽  
Christina Dornack
Keyword(s):  
Natural Attenuation ◽  
Contaminated Sites ◽  
Contaminated Site ◽  
Side Reactions ◽  
Flow Mode ◽  
Biological Degradation ◽  
Simultaneous Formation ◽  
Oxidation Of Sulfides ◽  
Soil Zone ◽  
Nitrate Consumption

Abstract Background Organic pollutants at contaminated sites are often eliminated naturally by biological degradation. The redox processes responsible can be enhanced by infiltrating electron acceptors such as nitrate or sulfate into the aquifer. However, the addition of oxidative agents can lead to undesired side-effects in the saturated soil zone such as the consumption of nitrate by the oxidation of sulfides contained in the aquifer. Laboratory-scale 1D column experiments in up flow mode were performed to evaluate the potential consumption of nitrate and the related kinetics by the oxidation of sulfides during an enhanced natural attenuation project at a site contaminated with monoaromatic compounds and trimethylbenzene. Water containing nitrate was infiltrated into aquifer soil material containing sulfides. To study side reactions, experiments were conducted with low levels of organic hazardous compounds. Results The results indicate that sulfide was oxidized with the simultaneous formation of sulfate by nitrate-consuming processes. The degradation rate of sulfide was calculated to be 1.26 mg kg−1 per exchanged pore volume, corresponding to nitrate consumption of 8.5 mg kg−1 in the case of incomplete denitrification and 3.4 mg kg−1 in the case of complete denitrification. Conclusion The presence of sulfides contained in the soil leads to a nitrate-consuming redox reaction following a linear function in case of sufficient availability of nitrate. This information is helpful for planning ENA projects at contaminated sites to reduce the risk of under- or overdosing the electron acceptor nitrate, which may lead to a lack of nitrate needed to enhance the biodegradation of contaminants in the aquifer or to the deterioration of groundwater quality.

Sign in / Sign up

Export Citation Format

Share Document